The present invention relates generally to an ink-supplied printer head being supplied with ink from an ink supply tank and more particularly to an ink supply tank which allows for the continuous supply of ink to the printer head while avoiding adverse effects from temperature, atmospheric changes or vibrations. The present invention allows for a larger volume of ink in the ink supply tank and allows for a greater percentage of the ink in the tank to be transferred to the printer head. Also, the present invention comprises a tank with transparent sides so the user is able to easily determine the remaining quantity of ink, and also means for dampening of the unwanted movement of ink within the ink supply tank.
This invention also relates to an ink cartridge for an ink jet printer in which an ink jet recording head, and an ink cartridge are mounted on a movable carriage, and in particular an ink jet cartridge in which upon depletion of the ink from the old cartridge, is replaced with a new ink cartridge.
Ink supply systems for a wire dot matrix printer are known in which no ink ribbon is used, but ink is supplied from an ink tank to the distal ends of the wire and transferred from the wires directly to a sheet of print paper. Portions of these ink supply systems, including the supply tanks thereof, are also adaptable to be used in ink jet type printers.
In the prior art, improved ink storage and delivery was achieved by providing a porous member in an ink tank that essentially filled the tank and carried essentially the entire supply of ink. It was found that while this construction offered substantial improvement over the prior art, the use of the full porous member limited the quantity of ink which would be stored in an ink tank of a given size, increasing the frequency of ink tank replacement.
A prior art ink jet printer in which an ink containing unit and an ink jet recording head are mounted on a carriage is disclosed in European Patent Publication No. 581,531. In the disclosed printer, in order to prevent printing failures caused by variation of the ink level or air bubbles due to movement of the ink cartridge, which is caused by the movement of the carriage, the ink container is divided into two regions. A first region of the container adjacent the recording head houses ink impregnated in a porous member, and a second region contains liquid ink without a porous member. This structure enables the ink to be conducted to the recording head via the porous member so that the problems arising from movement of the ink in the cartridge are prevented from occurring to a certain extent.
The porous member is held in fluid communication with the recording head by a projecting member which is inserted through a hole formed in the side portion of the container. However, such a structure cannot be applied to a recording head in which air bubbles must be stopped from entering a pressurized chamber, such as that for an ink jet printer in which a piezoelectric vibrator is used as an actuator for ink ejection.
Accordingly, a ink jet printer which solves the above-mentioned problems is derived.